[SOLVED] Restored vm - network problem

[liska_]

Hi,
I have a strange problem which I am not able to solve.
When I restore vm machine from backup, I can not make network working again. It was not a problem until proxmox 4.x.
If I ping google.com or internal network IP I get around 97% packet loss, few packets in a row are successful then many failed and this behavior is repeating. No firewall settings there.
I tried restore linux machines with 2.x and 3.x kernels with the same problem. I tried delete old network cards and create a new ones of various types without any improvement. Also changing MAC of old cards did not make any difference.
When I create a new machine, network is working without any problem. Also the original machines has no problem as well. There is no difference in config files except MAC addresses or network card types. Also restored vms has network problems on all nodes of my cluster where other vms are working flawlessly.
Those vms were created in older versions of proxmox 2.x or 3.x. I tried it on another cluster running proxmox 4.x (latest updates) with exactly same behavior.

Thank you for your help

 

[liska_]

Well, after trying this for few hours last week and after letting it be now for some time, it was resolved by itself. Probably some network stack problem, but very strange to me. I just have to wait for few minutes before managing restored vm ...

 

[Peter123]

Old thread, I know, but, we had the same problems after restoring some SQL servers on new Proxmox-servers.

Took as two days to find out that it was no problem with the Proxmox-network, but the windows client network: after resetting the NIC-MAC, the Windows client finally got connected to the WAN.

P.S.: also the NIC-devices AND the NIC-driver in Windows has to be removed completely in device-manager and to be reinstalled